Long noncoding RNAs (lncRNA) look like messenger RNA, with a 5’ cap and poly-adenylated tail, though it’s a mystery why they go untranslated. LncRNAs inhabit what Bernhard Dichtl, an RNA researcher at Deakin University in Australia, calls a “shadow world of gene expression.” Although their function is still not fully understood, they often appear to be involved in repressing gene transcription.
Many lncRNA codes are situated in the same location as the genes they repress, but on the opposite strand, such that their codes run in the reverse direction. Transcription of lncRNA code is thought to repress gene expression by blocking transcription factors or recruiting chromatin remodeling proteins. This would suggest that the lncRNA message itself is superfluous to its function as a repressor. But that idea didn’t quite make sense to Sarah Geisler, who studies RNA turnover in Jeff Coller’s lab at Case Western Reserve University in Ohio. Why ...
